Further Java Modernization

docs/documentation/formats.md

@@ -22,7 +22,7 @@ attributes using randomly generated data in the following way:
         Collection<Xml.XmlNode> address = faker.<Xml.XmlNode>collection()
                 .suppliers(() -> new Xml.XmlNode("address",
                         map(entry("country", faker.address().country()),
-                                entry("city", faker.address().city()), entry("streetAddress", faker.address().streetAddress())), Collections.emptyList()))
+                                entry("city", faker.address().city()), entry("streetAddress", faker.address().streetAddress())), List.of()))
                 .maxLen(3).build().get();
 
         Collection<Xml.XmlNode> persons = faker.<Xml.XmlNode>collection()

docs/documentation/schemas.md

@@ -271,13 +271,13 @@ INSERT INTO "MyTable" ("ints") VALUES (ARRAY[1, 2, 3]);
 === "Java"
 
     ```java
-    Schema.of(field("names_multiset", () -> Collections.singleton("hello")));
+    Schema.of(field("names_multiset", () -> Set.of("hello")));
     ```
 
 === "Kotlin"
 
     ```kotlin
-    val schema: Schema<String, Set<String>> = Schema.of(field("names_multiset", Supplier { Collections.singleton("hello") } ))
+    val schema: Schema<String, Set<String>> = Schema.of(field("names_multiset", Supplier { Set.of("hello") } ))
     ```
 
 will lead to
@@ -356,9 +356,9 @@ The following is an example on how to use it:
         field("lastname", () -> faker.name().lastName()),
         field("phones", () -> Schema.of(
             field("worknumbers", () -> ((Stream<?>) faker.<String>stream().suppliers(() -> faker.phoneNumber().phoneNumber()).maxLen(2).build().get())
-                .collect(Collectors.toList())),
+                .toList()),
             field("cellphones", () -> ((Stream<?>) faker.<String>stream().suppliers(() -> faker.phoneNumber().cellPhone()).maxLen(3).build().get())
-                .collect(Collectors.toList()))
+                .toList())
         )),
         field("address", () -> Schema.of(
             field("city", () -> faker.address().city()),
@@ -549,9 +549,9 @@ The following is an example on how to use it:
         field("lastname", () -> faker.name().lastName()),
         field("phones", () -> Schema.of(
             field("worknumbers", () -> ((Stream<?>) faker.<String>stream().suppliers(() -> faker.phoneNumber().phoneNumber()).maxLen(2).build().get())
-                .collect(Collectors.toList())),
+                .toList()),
             field("cellphones", () -> ((Stream<?>) faker.<String>stream().suppliers(() -> faker.phoneNumber().cellPhone()).maxLen(3).build().get())
-                .collect(Collectors.toList()))
+                .toList())
         )),
         field("address", () -> Schema.of(
             field("city", () -> faker.address().city()),

src/main/java/net/datafaker/providers/base/Fingerprint.java

@@ -65,7 +65,7 @@ private PatternType randomType() {
     }
 
     private byte[] encodePng(BufferedImage image) {
-        try (ByteArrayOutputStream baos = new ByteArrayOutputStream()) {
+        try (var baos = new ByteArrayOutputStream()) {
             ImageIO.write(image, "PNG", baos);
             return baos.toByteArray();
         } catch (IOException e) {

src/main/java/net/datafaker/providers/base/Image.java

@@ -150,7 +150,7 @@ private String generateBase64RasterImage(ImageType imageType, int width, int hei
         }
         graphics.dispose();
 
-        try (ByteArrayOutputStream baos = new ByteArrayOutputStream()) {
+        try (var baos = new ByteArrayOutputStream()) {
             ImageIO.write(bufferedImage, imageType.name(), baos);
             byte[] imageBytes = baos.toByteArray();
             return "data:" + imageType.mimeType + ";base64," + Base64.getEncoder().encodeToString(imageBytes);

src/main/java/net/datafaker/providers/base/Internet.java

@@ -10,7 +10,6 @@
 import java.nio.ByteBuffer;
 import java.text.Normalizer;
 import java.util.Arrays;
-import java.util.Collections;
 import java.util.List;
 import java.util.UUID;
 import java.util.regex.Pattern;
@@ -135,7 +134,7 @@ private String toLocalPart(String name) {
         final List<String> prefixList = (prefixObj instanceof List<?> list
                 && list.stream().allMatch(String.class::isInstance))
                         ? list.stream().map(String.class::cast).toList()
-                        : Collections.emptyList();
+                        : List.of();
         if (prefixList.contains(parts[0])) {
             parts = Arrays.copyOfRange(parts, 1, parts.length);
         }
@@ -144,7 +143,7 @@ private String toLocalPart(String name) {
         final List<String> suffixList = (suffixObj instanceof List<?> list
                 && list.stream().allMatch(String.class::isInstance))
                         ? list.stream().map(String.class::cast).toList()
-                        : Collections.emptyList();
+                        : List.of();
         if (suffixList.contains(parts[parts.length - 1])) {
             parts = Arrays.copyOfRange(parts, 0, parts.length - 1);
         }

src/main/java/net/datafaker/providers/base/Options.java

@@ -1,6 +1,5 @@
 package net.datafaker.providers.base;
 
-import java.util.Collections;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
@@ -76,7 +75,7 @@ public final <E> Set<E> subset(int size, E... options) {
             throw new IllegalArgumentException("size should be not negative: " + size);
         }
         if (size == 0) {
-            return Collections.emptySet();
+            return Set.of();
         }
         List<E> opts = Stream.of(options).distinct().collect(Collectors.toList());
         if (size >= opts.size()) {
@@ -119,7 +118,7 @@ public final Set<String> subset(int size, String... options) {
             throw new IllegalArgumentException("size should be not negative: " + size);
         }
         if (size == 0) {
-            return Collections.emptySet();
+            return Set.of();
         }
         List<String> opts = Stream.of(options).distinct().collect(Collectors.toList());
         if (size >= opts.size()) {

src/main/java/net/datafaker/service/FakeValues.java

@@ -15,7 +15,6 @@
 import java.util.Set;
 import java.util.concurrent.ConcurrentHashMap;
 
-import static java.util.Collections.emptyMap;
 import static net.datafaker.internal.helper.JavaNames.toJavaNames;
 
 public class FakeValues implements FakeValuesInterface {
@@ -41,7 +40,7 @@ private Map<String, Object> loadFromUrl() {
         if (url == null) {
             return null;
         }
-        try (InputStream stream = url.openStream()) {
+        try (var stream = url.openStream()) {
             Map<String, Object> result = readFromStream(stream);
             enrichMapWithJavaNames(result);
             return result;
@@ -64,12 +63,12 @@ private Map<String, Object> loadValues() {
                 "/" + locale.getLanguage() + ".yml"};
 
         for (String path : paths) {
-            try (InputStream stream = getClass().getResourceAsStream(path)) {
+            try (var stream = getClass().getResourceAsStream(path)) {
                 if (stream != null) {
                     result = readFromStream(stream);
                     enrichMapWithJavaNames(result);
                 } else {
-                    try (InputStream stream2 = getClass().getClassLoader().getResourceAsStream(path)) {
+                    try (var stream2 = getClass().getClassLoader().getResourceAsStream(path)) {
                         result = readFromStream(stream2);
                         enrichMapWithJavaNames(result);
                     }
@@ -82,21 +81,21 @@ private Map<String, Object> loadValues() {
                 return result;
             }
         }
-        return emptyMap();
+        return Map.of();
     }
 
     private void enrichMapWithJavaNames(Map<String, Object> result) {
         if (result != null) {
             Map<String, Object> map = null;
-            for (Map.Entry<String, Object> entry : result.entrySet()) {
+            for (var entry : result.entrySet()) {
                 final String key = entry.getKey();
                 Object value = entry.getValue();
-                if (entry.getValue() instanceof Map) {
+                if (value instanceof Map<?, ?> rawMap) {
                     @SuppressWarnings("unchecked")
-                    Map<String, Object> entryMap = (Map<String, Object>) entry.getValue();
+                    Map<String, Object> entryMap = (Map<String, Object>) rawMap;
                     prefixUnqualifiedExpressions(entryMap, key);
                     Map<String, Object> nestedMap = new HashMap<>(entryMap.size());
-                    for (Map.Entry<String, Object> e: entryMap.entrySet()) {
+                    for (var e : entryMap.entrySet()) {
                         nestedMap.put(toJavaNames(e.getKey(), true), e.getValue());
                     }
                     entryMap.putAll(nestedMap);

src/main/java/net/datafaker/service/FakeValuesGrouping.java

@@ -3,9 +3,9 @@
 import net.datafaker.service.files.EnFile;
 
 import java.util.Collection;
-import java.util.Collections;
 import java.util.HashMap;
 import java.util.HashSet;
+import java.util.List;
 import java.util.Locale;
 import java.util.Map;
 
@@ -27,12 +27,12 @@ public FakeValuesGrouping(FakeValues values) {
     }
 
     public void add(FakeValuesInterface fakeValue) {
-        if (fakeValue instanceof FakeValues) {
-            ((FakeValues) fakeValue).getPaths().forEach(p ->
+        if (fakeValue instanceof FakeValues values) {
+            values.getPaths().forEach(p ->
             fakeValues.computeIfAbsent(p, key -> new HashSet<>())
                 .add(fakeValue));
-        } else if (fakeValue instanceof FakeValuesGrouping) {
-            fakeValues.putAll(((FakeValuesGrouping) fakeValue).fakeValues);
+        } else if (fakeValue instanceof FakeValuesGrouping grouping) {
+            fakeValues.putAll(grouping.fakeValues);
         } else {
             throw new RuntimeException(fakeValues.getClass().getName() + " not supported (please raise an issue)");
         }
@@ -42,7 +42,7 @@ public void add(FakeValuesInterface fakeValue) {
     @SuppressWarnings({"unchecked", "rawtypes"})
     public Map get(String key) {
         Map result = null;
-        for (FakeValuesInterface fakeValues : fakeValues.getOrDefault(key, Collections.emptyList())) {
+        for (FakeValuesInterface fakeValues : fakeValues.getOrDefault(key, List.of())) {
             if (result == null) {
                 result = fakeValues.get(key);
             } else {

src/main/java/net/datafaker/service/FakeValuesService.java

@@ -31,7 +31,6 @@
 import java.util.Collection;
 import java.util.HashMap;
 import java.util.IdentityHashMap;
-import java.util.Iterator;
 import java.util.List;
 import java.util.Locale;
 import java.util.Map;
@@ -42,8 +41,6 @@
 import java.util.logging.Logger;
 import java.util.stream.Collectors;
 
-import static java.util.Collections.emptyList;
-import static java.util.Collections.emptyMap;
 import static java.util.Locale.ROOT;
 import static java.util.Objects.requireNonNull;
 import static java.util.logging.Level.FINE;
@@ -144,8 +141,8 @@ public void addUrl(Locale locale, URL url) {
     public Object fetch(String key, FakerContext context) {
         List<?> valuesArray = null;
         final Object o = fetchObject(key, context);
-        if (o instanceof List) {
-            valuesArray = (List<?>) o;
+        if (o instanceof List<?> list) {
+            valuesArray = list;
             final int size = valuesArray.size();
             if (size == 0) {
                 return null;
@@ -165,23 +162,12 @@ public String fetchString(String key, FakerContext context) {
         return (String) fetch(key, context);
     }
 
-    private class SafeFetchResolver implements ValueResolver {
-        private final String simpleDirective;
-        private final FakerContext context;
-
-        private SafeFetchResolver(String simpleDirective, FakerContext context) {
-            this.simpleDirective = simpleDirective;
-            this.context = context;
-        }
+    private record SafeFetchResolver(FakeValuesService service, String simpleDirective, FakerContext context)
+        implements ValueResolver {
 
         @Override
         public Object resolve() {
-            return safeFetch(simpleDirective, context, null);
-        }
-
-        @Override
-        public String toString() {
-            return "%s[simpleDirective=%s, context=%s]".formatted(getClass().getSimpleName(), simpleDirective, context);
+            return service.safeFetch(simpleDirective, context, null);
         }
     }
 
@@ -206,8 +192,8 @@ public String safeFetch(String key, FakerContext context, String defaultIfNull)
         Object o = fetchObject(key, context);
         String str;
         if (o == null) return defaultIfNull;
-        if (o instanceof List) {
-            final List<String> values = (List<String>) o;
+        if (o instanceof List<?> list) {
+            final List<String> values = (List<String>) list;
             final int size = values.size();
             return switch (size) {
                 case 0 -> defaultIfNull;
@@ -250,8 +236,8 @@ public <T> T fetchObject(String key, FakerContext context) {
             Object currentValue = fakeValuesInterfaceMap.get(sLocale);
             for (int p = 0; currentValue != null && p < path.length; p++) {
                 String currentPath = path[p];
-                if (currentValue instanceof Map) {
-                    currentValue = ((Map<?, ?>) currentValue).get(currentPath);
+                if (currentValue instanceof Map<?, ?> map) {
+                    currentValue = map.get(currentPath);
                 } else {
                     currentValue = ((FakeValuesInterface) currentValue).get(currentPath);
                 }
@@ -264,7 +250,7 @@ public <T> T fetchObject(String key, FakerContext context) {
         }
         if (local2Add != null) {
             Object valueToCache = result;
-            Object curResult = key2fetchedObject.getOrDefault(local2Add, emptyMap()).get(key);
+            Object curResult = key2fetchedObject.getOrDefault(local2Add, Map.of()).get(key);
             if (curResult != null) {
                 return (T) result; // Strange... Why return result, not curResult?
             }
@@ -683,14 +669,14 @@ private String[] splitExpressions(String expression, int length) {
     private Object resExp(String directive, String[] args, Object current, ProviderRegistration root, FakerContext context, String expr) {
         Object res = resolveExpression(directive, args, current, root, context);
         LOG.fine(() -> "resExp(%s [%s]) current: %s, root: %s, context: %s, expr: %s -> res: %s".formatted(directive, Arrays.toString(args), current, root, context, expr, res));
-        if (res instanceof CharSequence) {
-            if (((CharSequence) res).isEmpty()) {
+        if (res instanceof CharSequence charSequence) {
+            if (charSequence.isEmpty()) {
                 regexp2SupplierMap.put(expr, new RegExpContext(root, context, EMPTY_STRING));
             }
             return res;
         }
-        if (res instanceof List) {
-            Iterator<ValueResolver> it = ((List<ValueResolver>) res).iterator();
+        if (res instanceof List<?> list) {
+            var it = ((List<ValueResolver>) list).iterator();
             while (it.hasNext()) {
                 Object valueResolver = it.next();
                 Object value;
@@ -729,8 +715,8 @@ private Object resolveExpression(String directive, String[] args, Object current
             // resolve method references on CURRENT object like #{number_between '1','10'} on Number or
             // #{ssn_valid} on IdNumber
             if (dotIndex == -1) {
-                if (current instanceof AbstractProvider) {
-                    final Method method = BaseFaker.getMethod((AbstractProvider<?>) current, directive);
+                if (current instanceof AbstractProvider<?> provider) {
+                    final Method method = BaseFaker.getMethod(provider, directive);
                     if (method != null) {
                         res.add(new MethodResolver(method, current, args));
                         return res;
@@ -757,7 +743,7 @@ private Object resolveExpression(String directive, String[] args, Object current
         // car.wheel will be looked up in the YAML file.
         // It's only "simple" if there aren't args
         if (args.length == 0) {
-            res.add(new SafeFetchResolver(simpleDirective, context));
+            res.add(new SafeFetchResolver(this, simpleDirective, context));
         }
 
         // resolve method references on faker object like #{regexify '[a-z]'}
@@ -777,7 +763,7 @@ private Object resolveExpression(String directive, String[] args, Object current
         // class.method_name (lowercase)
         if (dotIndex >= 0) {
             final String key = javaNameToYamlName(simpleDirective);
-            res.add(new SafeFetchResolver(key, context));
+            res.add(new SafeFetchResolver(this, key, context));
         }
 
         return res;
@@ -922,10 +908,10 @@ private MethodAndCoercedArgs accessor(Class<?> clazz, final String accessorName,
         LOG.fine(() -> "Find accessor named %s on %s with args %s".formatted(accessorName, clazz.getSimpleName(), Arrays.toString(args)));
         String name = removeUnderscoreChars(accessorName);
 
-        Map<String, Collection<Method>> classMethodsMap = CLASS_2_METHODS_CACHE.computeIfAbsent(clazz, (__) -> {
+        var classMethodsMap = CLASS_2_METHODS_CACHE.computeIfAbsent(clazz, (__) -> {
             Method[] classMethods = clazz.getMethods();
             Map<String, Collection<Method>> methodMap =
-                classMethods.length == 0 ? emptyMap() : new HashMap<>(classMethods.length);
+                classMethods.length == 0 ? Map.of() : new HashMap<>(classMethods.length);
             for (Method m : classMethods) {
                 String key = m.getName().toLowerCase(ROOT);
                 methodMap.computeIfAbsent(key, k -> new ArrayList<>()).add(m);
@@ -934,7 +920,7 @@ private MethodAndCoercedArgs accessor(Class<?> clazz, final String accessorName,
             return methodMap;
         });
 
-        Collection<Method> methods = classMethodsMap.getOrDefault(name, emptyList());
+        Collection<Method> methods = classMethodsMap.getOrDefault(name, List.of());
         if (methods.isEmpty()) {
             LOG.fine(() -> "Didn't find accessor named %s on %s with args %s".formatted(accessorName, clazz.getSimpleName(), Arrays.toString(args)));
             return null;

src/main/java/net/datafaker/transformations/CsvTransformer.java

@@ -2,8 +2,6 @@
 
 import net.datafaker.sequence.FakeSequence;
 
-import java.util.Iterator;
-
 public class CsvTransformer<IN> implements Transformer<IN, CharSequence> {
     public static final String DEFAULT_SEPARATOR = ";";
     public static final char DEFAULT_QUOTE = '"';
@@ -46,7 +44,7 @@ public String generate(Iterable<IN> input, Schema<IN, ?> schema) {
         StringBuilder sb = new StringBuilder();
         generateHeader(schema, sb, true);
 
-        Iterator<IN> iterator = input.iterator();
+        var iterator = input.iterator();
         boolean hasNext = iterator.hasNext();
         while (hasNext) {
             IN in = iterator.next();
@@ -61,8 +59,8 @@ public String generate(Iterable<IN> input, Schema<IN, ?> schema) {
     }
 
     private void addLine(StringBuilder sb, Object transform) {
-        if (transform instanceof CharSequence) {
-            addCharSequence(sb, (CharSequence) transform);
+        if (transform instanceof CharSequence charSequence) {
+            addCharSequence(sb, charSequence);
         } else {
             sb.append(transform);
         }